I'm thinking of things along the lines of how "The Protocols of the Elders of Zion" came to be so widespread and adapted from a play (as I understand) or when people began denying the Moon Landing, the Holocaust, etc. I'm particularly interested in how these ideas are initially disseminated and elevated from fringe to dogma for some. This question is inspired by the guy with the Holocaust Denier father in law.
You might be interested in A Specter Haunting Europe by Paul Hanebrink. It addresses the long-running myth of Judeo-Bolshevism, in Europe primarily.
I'd recommend A Culture of Conspiracy: Apocalyptic Visions in Contemporary America by Michael Barkun. It doesn't touch on the Moon landing conspiracy in great detail, but does talk about the spread of The Protocols of the Elders of Zion. Its real strength is just what the title suggests: an examination of how conspiracies originate, evolve, and are disseminated in modern America, and how those processes have been changed by the Internet. Barkun categorizes conspiracies in a way that I think is really appropriate for the Internet era, from smaller event-focused conspiracies like the JFK assassination or Moon landing, to "superconspiracies" like the New World Order that pull in any number of smaller conspiracies into a larger structure.
The book was published in 2003, and when I read it a second time a few months ago, it was astonishing how prescient and applicable it is in 2021. QAnon fits Barkun's definition of a superconspiracy to a T. I really can't recommend it highly enough.
Hi there anyone interested in recommending things to OP! While you might have a title to share, this is still a thread on /r/AskHistorians, and we still want the replies here to be to an /r/AskHistorians standard - presumably OP would have asked at /r/history or /r/askreddit if they wanted non-specialist opinion. So give us some indication why the thing you're recommending is valuable, trustworthy, or applicable! Posts that provide no context for why you're recommending a particular podcast/book/novel/documentary/etc, and which aren't backed up by a historian-level knowledge on the accuracy and stance of the piece, will be removed.